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Category

Published on

05 Jul 2017

Abstract

For light-harvesting complexes (i.e. the Fenna-Matthews-Olson complex) or model systems with less than 8 sites, you can calculate absorption spectra, two-dimensional echo-spectra, and track the exciton populations and coherences.

GPU-HEOM handles non-Markovian effects and works well in the biologically relevant temperature range.

assumptions

independent phonon baths attached to each site, the same shape of the spectral density J(omega) is taken for each independent bath

decomposition of the vibronic spectral density into a superposition of shifted Lorentzian peaks

high-temperature approximation

for two-dimensional spectra, the program computes up to six Feynman pathways 4, and constructs the manifolds for the two exciton states as described in 5

caveats

convergence must be verified by increasing the hierarchy depth (be careful, this quickly exhausts the available GPU memory) and by decreasing the time-step. We recommend to start from the examples provided.